This invention relates to plugs which are used for connecting wire leads to audio signal devices and the like. More particularly, this invention relates to an improved male plug containing a collet for quickly securing a wire lead in the plug.
Plugs of the type to which this invention is particularly directed, usually comprise a cylindrical stem or insert section having a conically shaped tip, which in use is removably inserted into a cylindrically shaped receptacle of the type frequently found in phonograph housing, amplifier housings, electric guitars, and the like. Plugs of this type are also commonly referred to as phone jacks or phono jacks.
This invention relates particularly to an improvement over a plur or jack of the type disclosed in U.S. Pat. No. 4,145,566, wherein a collet sleeve is positioned in the plug housing at the cord inlet end thereof, which is the end opposite to that from which the stem or insert section projects. One major problem with this type of jack is that the associated collet must be provided with internal or external threads, so that after one end of an electrical cord has been inserted into the collet, the latter can be drawn axially rearwardly in the plug housing toward its inlet end in order to cause the collet pressure elements to be urged radially inwardly into gripping engagement with the associated cord. This construction also requires a separte bushing to be threaded over the inlet end of the housing in order to grasp and draw the threaded collet axially with respect to the housing.
In addition to being rather expensive to manufacture this known type of plug also has the disadvantage that the threaded portions of the collet tend to fail after repreated use. Also, once the threads are stripped, the plug is no longer of any use.
It is an object of this invention, therefore, to provide an improved plug of the type described which includes a collet that can be made without the use of any internal or external threads thereon. Moreover, the collet employed in this invention is not subjected to any axial tensile forces in order to effect closure of its cord gripping jaws.
Still another object of this invention is to provide an improved plug of the type described in which the collet is shifted axially within the plug housing under compressive stresses, rather than tensile stresses. It is an object also, therefore, to construct the plug in such manner that the collet is urged axially into an active position by the male end of the plug, which is releasably threaded into the plug housing compressibly to engage and urge one end of the collet axially into an operative position in the housing.
Other objects of the invention will be apparent hereinafter from the specification and from the recital of the appended claims, particularly when read in conjunction with the accompanying drawing.